※ 引述《honu (水母)》之銘言： : http://www.sciencedaily.com/releases/2007/05/070530132405.htm : 出自Sciencedaily網站，這個網站還蠻好看的，英文不難 : 不過暫時沒力氣翻了，有人要接手嗎？ 剛好吃飽沒事做....XDD : Detecting Cold, Feeling Pain: Study Reveals Why Menthol Feels Fresh : Science Daily — Scientists have identified the receptor in cells of the : peripheral nervous system that is most responsible for the body's ability to : sense cold. 測冷感痛: 研究揭露薄荷腦令人感到清爽的秘密! 科學每日－科學家已發現位於邊緣神經系統中的特定受器, 該受器負責身體感覺寒冷的能力。 : The finding, reported on-line in the journal "Nature" (May 30, 2007), reveals : one of the key mechanisms by which the body detects temperature sensation. : But in so doing it also illuminates a mechanism that mediates how the body : experiences intense stimuli -- temperature, in this case -- that can cause : pain. 這項發現於期刊"自然"(2007/5/30)線上發表後, 揭示了人體偵測溫度知覺的關鍵機制之一。 這項研究同樣地也點亮了調節身體經歷強烈刺激而產生痛覺的機制, 在這個例子中, 這個刺激便是溫度。 : As such, the receptor -- known as menthol receptor TRPM8 -- provides a target : for studying acute and chronic pain, as can result from inflammatory or nerve : injury, the researchers say, and a potential new target for treating pain. 就該受器－－正確名稱為「薄荷腦受器TRPM8」－－而言, 提供了研究刺痛與慢性疼痛的指標, 這些疼痛可能由發炎或神經受損所導致, 研究者表示, 這將是治療疼痛具有前景的新指標。 : "By understanding how sensory receptors work, how thresholds for temperature : are determined, we gain insight into how these thresholds change in the : setting of injury, such as inflammatory and nerve injury, and how these : changes may contribute to chronic pain," says senior author David Julius, : PhD, chairman and professor of physiology at UCSF. UCSF生理學博士、系長兼教授資深研究者大衛朱立思說: 瞭解感覺受器運作的原理、溫度絕對閾的測定, 使得我們能夠洞察這些閾值在受傷時、發炎時以及神經受損時的改變, 這些改變或許會導致慢性疼痛。 : The menthol receptor, and other temperature receptors discovered in recent : years by the Julius lab, offer potential targets for developing analgesic : drugs that act in the peripheral, nervous system, rather than centrally, : where opiate receptors act, he says. 大衛說, 薄荷腦受器以及進幾年在朱立思的實驗室中發現的其餘幾個溫度受器, 將提供發展作用於邊緣神經系統的止痛藥一個具有前景的指標, 而不項以往的止痛藥作用於麻醉或鎮定的受器。 : The finding is a milestone in an investigation the team began several years : ago. In 2002, the researchers discovered that the receptor was activated by : chemical cooling agents such as menthol, a natural product of mint, and cool : air. They reported their discovery, or "cloning," of the receptor in "Nature" : (March 7, 2002), hypothesizing that the receptor would play a key role in : sensing cold. However, some subsequent papers questioned this theory. 這項發現是該團隊進行調查幾年後一個重要的里程碑。 2002年, 研究人員發現某些受器會受化學冷卻傳導媒介所啟動, 這些傳導媒介有薄荷腦－－薄荷的自然產物、冷空氣。 他們在"自然"雜誌(2002/3/7)報告了他們對於這些受器的研究發現, 並假設這個受器在偵測寒冷時扮演了舉足輕重的角色。 然而一些後繼的研究報告動搖了這個理論。 === 耶～剛好翻到一半 有人要接力嗎 還是要等我洗完澡 XDDDD === : In the current study, the team confirmed their hypothesis by "knocking out" : the gene that synthesizes the receptor, both in sensory neurons in cell : culture and in mice. The cells in culture were unresponsive to cooling : agents, including menthol. The genetically engineered mice did not : discriminate between warm and cold surfaces until the temperature dropped to : extremes. : "It's been known for years that menthol and related cooling agents evoke the : psychophysical sensation of cold -- somehow by interacting with the aspect of : the sensory nervous system that's related to cold detection," says Julius. : The current study, he says -- led by Diana M. Bautista, PhD, and Jan Siemens, : PhD, of the Julius lab and Joshua M. Glazer, PhD, of the lab of co-senior : author Cheryl Stucky, PhD, of the Medical College of Wisconsin -- puts that : question to rest. : As the mice lacking the gene were not completely insensitive to cold -- they : avoided contact with surfaces below 10 degrees C, though with reduced : efficiency -- the next step, says Julius, will be to illuminate this residual : aspect of cold sensation. : The finding is the latest of a series of discoveries led by the Julius lab on : the molecular mechanisms of temperature sensation and pain. In 1997, the lab : cloned the gene for the capsaicin receptor, the main pungent ingredient in : some chili peppers (Nature, Oct. 23, 1997), and in 2000 reported that, in : mice, the receptor triggers the nerves to fire pain signals when they are : exposed to high ambient heat or the fiery properties of peppery food. : (Science, April 14, 2000). The study demonstrated that capsaicin and noxious : heat elicit the sensation of burning pain through activation of the same : receptor on sensory neurons. : Most recently, they identified the receptor of isothiocyanate compounds, : which constitute the pungent ingredients in such plants as wasabi and yellow : mustard. In response to high temperatures, the receptor produces pain and : irritation. : "All of these studies use natural products to understand pain mechanisms in : the periphery of the body, where they are first sensed," says Julius. : Ultimately, pain signals are transmitted from the peripheral nervous system : into the body's central nervous system -- moving through nerves in the spinal : cord and brain stem up to the brain, which prompts a response, or "feeling." : Co-author of the current study Allan Basbaum, PhD, also of UCSF, is a pioneer : of research into the mechanism of chronic pain within the central nervous : system. : The Julius team's complementary work is focused at the level of the sensory : nerve fiber, where the signals are first initiated. "We want to know," Julius : says, "how do you detect these stimuli to begin with" How do your sensory : nerve endings do this to begin with" And what are the biochemical and : biophysical mechanisms that account for this"" : All three receptors the Julius lab has discovered are members of the TRP : family of ion channels expressed on sensory neurons. The latest finding adds : to the evidence, says Julius, that TRP channels are the principal transducers : of thermal stimuli in the mammalian periphery nervous system. : Other co-authors of the study were Pamela R. Tsuruda, PhD, of UCSF, and : Sven-Eric Jordt, PhD, of Yale University School of Medicine. : The study was funded by the National Institutes of Health, the Burroughs : Welcome Fund and the Human Frontiers Science Program Organization. : Note: This story has been adapted from a news release issued by University of : California - San Francisco --

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